Summary

A reproducible single puncture medial pie-crusting technique which is specific to the site of meniscal lesion

Abstract

Introduction

Visualization in tight medial compartment is a common scenario while performing arthroscopy. To provide adequate access to the medial compartment, medial pie-crusting techniques are followed. Our study describes the science and technique of medial pie-crusting with a single puncture which is specific to the site of meniscal lesion (posterior horn or body) and evaluates the reproducibility of this technique.

Material & Methods:
The medial pie-crusting technique was done in a fresh frozen cadaver and the opening of the medial compartment specific to posterior horn of medial meniscus was visualized arthroscopically after a single puncture. The needle used for pie crusting was left in situ and dissection of the medial side of the knee was done to identify the structure that is being punctured to open the knee.

Visualising from the anterolateral portal, the probe is used through the anteromedial portal in direct line to palpate the posterior horn of medial meniscus. The probe is pinched at the skin level and removed. Keeping a switching stick horizontally from the anteromedial portal the probe is placed outside in the medial aspect of the knee to the same depth of posterior horn that was measured by pinching the probe. Puncture is done 12mm proximal to this point to pie-crust the medial aspect using a 18G needle. Similarly, to open the knee at the body of the meniscus, the probe is placed along the direct line from the anteromedial portal to the level of the body of meniscus and pie-crusting is done using this measurement.

The reproducibility of this technique was studied in 3 centres by 3 different surgeons. 30 consecutive knee arthroscopy cases done between September 1st 2023 to March 31st 3024 requiring medial compartment opening were taken into the study. If the surgeon is able to open the medial compartment of the knee specific to the site of the lesion after a single puncture of the skin, it was considered as “opening in first attempt”. The surgeon was allowed to slightly angulate the needle without removing it out of the skin puncture. If the surgeon had to remove the needle out of the skin puncture and make a new puncture, then it was considered as “missed in first attempt”. If the surgeon failed to open the medial compartment through this technique and had to resort to other techniques for opening the medial compartment, then it was considered as “failure of attempt”.

Result:
All cases in the first centre, 29 cases in the second centre and 29 cases in the third centre had opening in first attempt. One case in the second centre and one in the third centre had opening in the second attempt. The opening in first attempt percentage was 97.78% (88/90). There was no failure of attempt recorded.

Conclusion

This technique derived from anatomical cadaveric study translated into surgical practice. It is useful to open the medial compartment specific to the site of lesion of the medial meniscus. It is simple and reproducible in real operating room scenarios.